Recently, HD (High Definition) resolution broadcast services are spreading nationwide and worldwide, and many uses are familiar with high-resolution, high-quality images. Accordingly, many organizations put more energy on development of next-generation imaging apparatuses. Further, more interest is drawn to UHD (Ultra High Definition) that provides four times or more higher resolution than that of HDTV as well as HDTV, and thus, an compression technology is required for higher-resolution, higher-quality images.
For image compression, there may be used an inter prediction technology that predicts a pixel value included in a current picture from pictures that temporally come earlier and/or later than the current picture, an intra prediction technology that predicts a pixel value included in a current picture using pixel information in the current picture, and entropy encoding technology that allocates a shorter code to a symbol appearing more frequently and a longer code to a symbol appearing less frequently.